Piston for power engines



Feb. 25, 1941. c. RETSCHY L PISTON FOR POWER ENGINES Filed July '7, 1938 INVENToR ATTORNEYS Patented Feb. 25,l 1941 UNITED STATES Pis'roN Fon POWER ENGINES Curt Retschy, Winterthur, Switzerland,

assignor to Sulzer Freres, Societe Anonyme, Winterthur,

Switzerland Application .my 7, 193s.v semi No. 217,959

In switzerland .my 19, 1937 s claims. (ciL-,sosaoi This invention relates to pistons for power engines and the like, and has for its object the provision of an improvedvpiston and means for connecting the piston to its connecting rod. '.I'he improved apparatusof the invention comprises a piston having a ball joint between the piston and its connecting rod which permits movement of the piston in all directions, and means are provided for utilizing the swinging or pivoting movement of the connecting rod to impart to the piston a, continuous rotation with respect to the connecting rod, including expandable rings mounted in the piston and means for alternately bringing the rings into gripping and into s1ipl5 ping engagement with the piston.

The accompanying drawing illustrates a. construction and arrangement of apparatus in ac-v cordance with the invention, in which Fig. 1 is a longitudinal section along the line I-I of Fig. 2, an v Fig. 2 is a cross section along the line 2 2 of 'I'he piston I of the apparatus illustrated is of the type especially adapted for an opposed-piston combustion engine, and is connected to the connecting rod 2 which transmits the power of the piston through a balance lever 3I to an addif tional connectingtrod and a crankshaft (neither of which is shown). The connecting rod 2 has a ball head 4 which is in coupled engagement with two ball sockets 5 and 6 of the piston. The ball socket 5 lies on a shoulder 1 of the piston I, and the ball socket 6 rests against the ring screw or threaded sleeve 8 which is screwed into the lower end-portion of the piston I. By adiustment of the ring screw yIl the necessary bearing play of the ball pivot in its sockets can be obtained exactly. After the adjustment, the ring screw can be secured against rotation by a, threaded screw pin 9. I'he connecting rod 2 is thus mounted so that it can pivot`ln all directions with respect to the piston and is also rotatable around its own axis.

A cylindrical bushing I Il is inserted in the piston and secured against turning by means of a threaded screw pin II. On the inner surface of the bushing I0 rest two expandable split rings I2 and I3, both of which are split 0r slotted at point I4 and coaxial with respect to the piston.

The diameter of the split rings is made somewhat larger than the inner diameter of the bushing I0 so that they, after insertion in the bushing, exercise a pressure on the inner surface thereof. In other words, each split ring is under stress causing it to be in pressed engagement with the bushing or sleeve I0. Each split ring has an opening I5 and I6 near the split I4, in which control pins I1 and I8, respectively, of the bolt I9 are inserted. The bolt I9 is secured against turning with respect to the connecting rod 2 by means 5 of a pin 20. 'I'he bolt I9 is preferably coaxial with the pivotal center of the rod in the ball and the pins I5 and I6 are spaced from or eccentric with respect to the said pivotal center.

'I'he pivoting movements of the connecting rod 10 that-occur during operation are transmitted to the control pins I1 and I8 and to the split rings I2 and I3. If the controlpin II displaces the split ring I2 in the direction of fthe arrow 2I, then the ring tends to expand and as a result of 15 the increased stress frictionally engages the bushing Ill and the piston I, thus imparting to the piston a rotating movement. If, conversely, the control pin Il is displaced in the direction of the arrow 22, it will contract the split -ring les- 20 sening the strs and loosen it fromthe bushing I0. 'I'he bushing I 0 and the piston will then notV participatein the movement. The inner surface of the bushing I0 will then slide over the outer surface of the split ring.

'I'he control pin I8 makes the same movements as the control pin I'I, but so displaced as regards time that the split ring I3 is loosened when the ring I2 is expanded and vice versa. In other words, each ring is alternately brought into 3o gripping and in'to slipping engagement with the bushing IIJ. I'hus the piston will be driven constantly in the direction of the arrow 2| by lthe control pins I1 and I8 so that it will also receive a turning motion in the direction of the 35 arrow 2| during its stroke movement.

The arrangement of the split rings I2 and I3, bushing I0 and the eccentrically mounted control pins I'I and I8 comprises a friction clutch coupling the piston to the rod and enabling swinging movement of the rod to rotate the piston. 40

In order to prevent the undesirable eiect of the oil film between the split rings I2 or I3 and the bushing I0, grooves 23 are turned in the rings so'that even with slight pressures the oil illm will be suppressed. 45 The advantage of the turning movement sui perposed on the axial movement of the piston causes the ball pivot to be ground in on all sides giving an exact ball surface. If foreign substances get between the slide surfaces of the 50 bearing, either at the ball joint or at the cylinder slide surface, they will not remain in a, Vxed or constant path, but will be brought to new points of the slide surface. The foreign substance will be rubbed away in very short time so that it cannot injure the bearing surface.

The same effect obtained by split rings can also be obtained by clamping rings placed around the cylindrical part of the piston which receive an oscillating turning movement `through the swing movement of the connecting rod. The oscillating turning movement of the clamping rings is then converted into a steady continuous turning movement of the piston. Furthermore, bevel gears may be used, one of which could be fastened to the connecting rod and another to the piston, one of the gears receiving a pawl drive so that by the pawl the piston would be driven in steadily continuous turning movement by the oscillating movement of the connecting rod.

The apparatus according to the invention may be so formed and operated that, in an engine having, for example, a speed of 1500 revolutions per minute, the piston may rotate 8 to 10 times per minute. The apparatus described permits a flexible drive of the piston so that when too great resistances to the turning movement of the piston occur, no part is excessively loaded .but the turning movement merely ceases. ,Y It is particularly important in this connection that a periodicity cannot result, ton ,in the cylinder result.-

The improved apparatus of the invention may also be applied to steam engines, pumps, compressors and other piston engines.

The ilexible drive has a special advantage because the exible ratchet couplings, for example, the clamping rings, split rings, ratchet locking,

etc., do not transmit too high forces to the pis-A tons so that no unpermissible loads occur. In particular, the accelerating or retarding forces in the intermittent drive will not receive too high values.' `The invention isA especially applicable in the case of engines with high speeds, and high bearing loads or stresses.

1. The combination with a piston which comprises a connecting rod ior the piston, a bali joint connection between the piston and the rod, two expandable rings mounted in the piston arranged to effect frictional engagement with the piston, and pivotal connecting means in engagement with the ball and with the rings responsive to the swinging movement of the rod for alternately expanding and contracting the rings bringing them alternately into slipping and into slipping engagement with the piston.

2. The combination with a piston which comprises a connecting rod for the piston, a ball at the piston end of the rod, seating members in the piston for mounting the piston on the ball, an expandable split ring mounted inside the pisthe friction surfaces of but new positions.4 ofthe pis' ton, pin means connected to the rod and to the ring near the split for expanding the ringl when the rod swings, said pin means being spaced from the pivotal center of the rod and arranged to expand and contract the ring alternately into gripping and into slipping engagement with the piston.

3. The combination with a piston which comprises a connecting rod for the piston, a ball at the piston end of the rod, seating members in the piston for mounting the piston on the ball, a sleeve secured to the piston and between the seating members, two expandable split rings coaxially mounted in the sleeve, and pin means on the ball in operative engagement with the rings, said pin means being arranged to oscillate about the axial center of the ball as the rod is swung and bring the rings alternately into frictional gripping engagement and into slipping engagement with the sleeve, thereby rotating the piston.

4. In the combination of claim 3, grooves on th'e rings for suppressing the action of the oil at the'irlction surfaces.

5. The combination with a piston which comprises a connecting rod for the piston, a ball at the piston and of the rod, seating members in the piston for'mounting the piston on the ball, a sleeve 'secured to the piston and between the seating members, two split rings mounted inside the sleeve under suillcient stress causing them -to be in gripping engagement with the sleeve, means for alternately moving the rings in one direction to move the piston therewith and for al rternately releasing them from gripping engagement causing one ring to slip in the sleeve while the other ring moves the piston, said means including two pins spaced'from the pivotal center of the ball each being in engagement with one of the rings near the split, said piston being rotated by the rings as the rod swings due to reciprocation of the piston.

6. The combination with a piston which comprises a connecting rod for the piston, a ball at th'e piston end of the rod, seating members in the piston for mounting the piston on the balll two split rings mounted inside the piston, means causing each ring to be in gripping engagement with the piston, means for moving one ring in one-direction while it is in gripping engagement with the piston to move the piston therewith, and means `for releasing the other ring from gripping engagement with the piston permitting it to slip as the piston is being moved by the other ring, said means for moving one ring in one'direction and releasing the other ring being in operative engagement with and actuated by the swinging movement of the piston rod.

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